1. Field of the Invention
One disclosed aspect of the embodiments relates to a method for manufacturing an energy ray detection device.
2. Description of the Related Art
As is known in the art, an energy ray detection device is manufactured as a semiconductor device using a widely used semiconductor process.
The energy ray detection device includes an active part having a charge generation element that generates signal charge, and a conductive contact portion connected to the active part, and detects the signal charge via the contact portion. Specifically, the contact portion is electrically connected to, for example, a gate of an amplifier transistor of an amplifier circuit, thus obtaining an amplified signal in accordance with the amount of signal charge. In order to accurately detect energy rays, it is effective to efficiently collect signal charge in a portion of the active part in the vicinity of the contact portion.
Japanese Patent Laid-Open No. 2000-312024 discloses that a plurality of regions (a second semiconductor region and an inner region) having different impurity concentrations are formed in a semiconductor region and therefore a potential gradient which enables charge to move towards an electrode region is formed.
Japanese Patent Laid-Open No. 2007-81083 discloses a line sensor in which a second impurity region includes a first portion and a second portion arranged so as to surround the first portion, and the first portion has a higher impurity concentration than the second portion.
In Japanese Patent Laid-Open No. 2000-312024, the second semiconductor region and the inner region are formed by forming a photoresist pattern twice and performing ion implantation using each photoresist pattern as a mask. This method may make it difficult to form a desired potential gradient, and sufficient signal charge may not necessarily be collected in the electrode region.